1. Field of the Invention
The present invention relates to a device for continuously measuring the skin local sweating rate including rate of emotional perspiration as well as that of heat-sensitive perspiration.
2. Description of the Prior Art
The devices for continuously measuring the skin local sweating rate are useful for a quantitative test of function of autonomic nervous system of a human body or sweating system for regulating body temperature, etc. Such devices are disclosed in Japanese Laid-Open Patent Publication Nos. 63-46131 and 63-57031.
The Japanese Laid-Open Patent Publication No. 63-46131 discloses a measuring device comprising a capsule and an air supply device. The capsule is applied on a skin at a sweating rate measuring point to form a chamber between the capsule and the skin. Air is supplied into the chamber from the air supply device, and the difference of the humidity of the air supplied into the chamber and discharged from the chamber is detected. The sweating rate at the measuring point is calculated based on the difference of the humidity thus detected.
The Japanese Laid-Open Patent Publication No. 63-57031 discloses a system comprising a dehumidifying device between a capsule and an air supply device. In this system, only one humidity sensor is required.
The prior art sweat measuring devices detect the relative humidity in the capsule, and the sweating rate is calculated on the assumption that the temperature of the capsule is invariable. However, the inventors of the present invention have proved that the influence of the variation in the capsule temperature cannot be neglected to obtain reliable sweating rate. Further, in these prior art devices, oscillators are fixed on the rear surfaces of the capsules and include the humidity detecting sensors as a circuit component, so that the frequency of the oscillators is varied according to not only the relative humidity but also to the temperature of the capsule and the temperature of the atmosphere. Therefore, accurate sweating rates could not be measured.